title: Neuromyelitis optica-IgG testing in an Indian cohort with neuromyelitis optica and related demyelinating disorders: Our experience.
abstract: BACKGROUND
  Neuromyelitis optica (NMO) is an immune-mediated inflammatory demyelinating disorder of the central nervous system with a predilection for the optic nerves and the spinal cord. Immunopathological evidence suggests that the target antigen of the disease is aquaporin-4. An IgG antibody against this protein has been explored as a molecular marker for the disease and as a diagnostic tool due to its high sensitivity and specificity in various populations.
  
  
  OBJECTIVE
  To assess the value of NMO-IgG testing in Indian patients with clinical and magnetic resonance imaging features consistent with NMO and longitudinally extensive transverse myelitis (LETM).
  
  
  METHODS
  Forty-five patients with clinical and magnetic resonance imaging features consistent with NMO, LETM, and MS were tested for serum NMO-IgG. Of these patients, 22 patients satisfied revised (2006) Wingerchuk criteria for NMO (excluding NMO-IgG status) and 11 patients had LETM. Twelve patients satisfied the revised (2010) McDonald criteria for multiple sclerosis (MS).
  
  
  RESULTS
  Of the 21 patients, satisfying the criteria for NMO and for whom the test results were available, 17 were positive for NMO-IgG (80.9%), and of the 11 patients having LETM, 6 (54.5%) were positive for NMO-IgG. In one patient with NMO, the test result was not available. None of the 12 patients satisfying McDonald criteria for MS showed NMO-IgG seropositivity.
  
  
  CONCLUSIONS
  Our study suggests that it is worthwhile to pursue NMO-IgG testing as a diagnostic tool for patients with clinical and Magnetic Resonance Imaging (MRI) features consistent with NMO and LETM in the Indian population.
authors.affiliation: Department of Neurology, Daya General Hospital, Trichur, India.
authors.forename: Narayanan
authors.initials: N
authors.lastname: Unni
authors.forename: Kavita
authors.initials: K
authors.lastname: Barhate
authors.forename: Nisha
authors.initials: N
authors.lastname: Ahmad
authors.forename: Malti
authors.initials: M
authors.lastname: Ganeshan
authors.forename: Bhim
authors.initials: B
authors.lastname: Singhal
keywords: Anti-aquaporin-4 seropositivity; neuromyelitis optica; neuromyelitis optica-Immunoglobulin G seropositivity; transverse myelitis